Azo dyestuffs of the pyrazolone series and process of making same



; Patented July 29, 1930 UNITED STATES PATENTOFFICE GERALD BoNHorE, or MONTANA, SWITZERLAND, Assmrion ro socIErY or CHEMICAL INDUSTRY IN BASLE, or BAsEnswITzERLA-Nn .AZO DYESTUFFS OF THE PYRAZOLONE SERIES AND PROCESS OF MAKING SAME No Drawing. Application filed November 20, 1928, Serial No. 320,751, and in Switzerland November The present invention relates to new azo dyestufl's of the pyrazolone series especially suitable for the dyeing of wool and silk. It comprisesthe process of making these products, the new products themselves and the material dyed therewith.

It has been found that new dyestuffs, which combine a good fastness to alkali, to washing and to acid fulling with an excellent fastness to light and an exceedingly good levelling power, are obtained by coupling diazotized dichloranilines, such as for instance 2:4- or 2: 5-dichloraniline, with such 1-aryl-3-methyl-5-pyrazolone-sulfonic acids the aryl nucleus of which contains besides the sulfo-group no other substituents than at least one halogen, as for example the 3- methyl-5-pyrazolones deriving from the monoor polyhalogen-anilinesulfonic acids, (such for example as 4-chloro-1-aniline-3- sulfonic acid or 2:.5-dichloro-l-aniline-4esulfonic acid), the chlorotoluidinesulfonic acids, and so on. The new dyestuffs, corresponding to the general formulawherein m is in two cases chlorine and in the three other hydrogemy in one case an SO H5 group, at least 1n one further case chlorlne,

converted into insoluble metal'salts and can i be used for making lacquers.

The following example illustrates the invention, the parts being by weight 16.2 parts of 2: 5-dichloraniline are diazotizedinthe usual manner. The diazo-solu tion is coupled'a-t 5-10 G. with a solution of 28.8 parts of 1- (2-chloro-5-sulfo)-phenyl- 3-methyl-5-pyrazolone containing sodium carbonatein excess. The coupling sets in at once. The solutionis stirred until the diazocompound has disappeared, the precipitated dyestuff is filtered and dried. It forms a yellow powder dissolving in water With a yellow coloration, and dyeing wool and silk from an acid :bath yellow tints which possess the valuable properties already above mentioned.

The new dyestuii may also be converted into insoluble metal salts and can be used for making lacquers. v r

What I claim is 1. Process for the manufacture of new azo-dyestufis corresponding to the general formula U three other hydrogen, 3 in one case an $O H- group, at least in one further case chlorine, and the rest,be1ng neither SO H nor chlorine,

, hydrogen, by coupling diazotized dichloranilines with such 1-aryl-3-methyl-5-pyrazolone sulfonic acids the aryl nucleus of which contains besides the sulfo-group no other substituents than at least one halogen atom. Q 7

2. Process-for the manufacture of new azodyestufls corresponding to the general formula- V p OH! wherein y is in one case an SO H-group,at

8. Process for the manufacture of the new azo-dyestufl corresponding to the formulaby coupling diazotized 2:5-dichloraniline with 1-(2-chloro-5-sulfo-) -phenyl-3-methyl- 5-pyrazolone.

4. As new products the azo-dyestufis of the general formula wherein m is in two cases chlorine andin the three other hydrogen, y in one case an SO H-group, at least in one further case chlorine, and the rest, being neither SO H nor chlorine, hydrogen, which dyestuffs form yellow powders, dissolving in water with a yellow coloration, and dyeing wool and silkfrom an acid bath yellow tints.

5. As new products the azo-dyestuifs of the general formula.

, i V y y 7 01 H -fiQ-v wherein y is in one case an so H-group, at least in one further case chlorine, and the 'rest,'being neither SO H nor chlorine, hydrogen, which dyestuffs form yellow powders, dissolving in water with a yellow coloration, and dyeing wool and silk from an acid bath yellow tints.

6. As a new product the azo-dyestufi of the formula which forms a yellow powder, dissolving in water with a yellow coloration, and dyeing wool and silk from an acid bath yellow tints. I

7 The material dyed with the products of claim 4. I .7 o I 7 8. The material dyed with the products of claim 5.

9. The material dyed with the product of claim 6. y

In witness whereof I have hereunto signed my name this 3rd da of November, 1928. BALD BONHOTE. 

